with Google IoT Core we implemented JSON Web Tokens (JWT) for the
MQTT Password, as standardized in RFC 7519 .
This allows for any number of devices publishing MQTT telemetry
with arbitrary authentication parameters to Google IoT Core or
any other IoT platform that requires JWT.
This is in addition to previous support for OAuth 2.0 .
The screenshot below shows 2 pulled subscriptions with unique
telemetry:
We have since improved our demo scenarios as detailed in this post.